Water column geochemistry data from REVOSIMA MAYOBS1 Cruise

the mayotte volcanological and seismological monitoring network (revosima) was created in response to the sub-marine eruption that started in may 2018. composed by ipgp, brgm, ifremer and cnrs, its main missions are: 1) to observe and study volcanic phenomena through real-time volcano monitoring, 2) to conduct research programs, 3) to communicate, disseminate and inform authorities and civil society.these real-time observations and research can contribute to the prevention, and mitigation of seismic and volcanic risks. the main objective is to collect geological, geophysical and geochemical data over long periods of time to improve the understanding and modeling of volcanic processes at active volcanoes, to allow the systematic elaboration of long-term multi-parameters databases available to the scientific community, and to inform the authorities in charge of civil protection of any change in the volcano activity and after periods of local and regionally felt earthquakes.the mayobs campaigns are carried out to monitor the evolution of the seismic and volcanic phenomenon which has affected the island of mayotte since may 2018. they are carried out as part of an action program financed by the ministry of research, the general directorate of prevention and risks of the ministry of ecological and inclusive transition, with the support of the interministerial delegate for major risks overseas and in conjunction with the other ministries and institutes involved (ipgp, ipgs, brgm, ifremer). they focus on the region east of mayotte. the bathymetric surveys carried out by shom in the volcano area also contribute to the mayobs project.ifremer carried out water column geochemistry measurements during md220-mayobs cruise. in the present database, 5 stations were investigated between 15th and 17th may 2019 using in situ measurements embedded in a ctd-rosette. samples (max. 16 bottles per station) were anaylized onboard and onshore depending on the parameters. the quality controlled and process data are: in situ: salinity (conductivity), temperature, depth, dissolved oxygen, turbidity onboard: ph, alkalinity, dissolved inorganic carbon onshore: dissolved co2 ch4 h2, silicates

马约特火山学及地震监测网络（Revosima）应马约特海域2018年5月开始发生的海底火山喷发而建立。该网络由IPGP、BRGM、IFREMER及CNRS共同组成，其主要使命包括：1）通过实时火山监测观察与研究火山现象；2）开展研究项目；3）向相关部门及民间社会进行沟通、传播与信息通报。这些实时观测与研究成果有助于地震和火山风险的预防和减轻。其核心目标是在长时间内收集地质、地球物理和地球化学数据，以深化对活动火山火山过程的认知与建模，确保科学界能够系统性地构建多参数长期数据库，并就火山活动及其后局部及区域地震的发生变化，向负责民防的当局提供信息。为监控自2018年5月起影响马约特岛的地震与火山现象的演变，实施了Mayobs活动。这些活动作为由研究部、生态包容性转型部预防与风险总司资助的行动计划的一部分，在海外重大风险跨部门代表的支持下，与其他相关部门和机构（IPGP、IPGS、BRGM、IFREMER）共同实施，重点关注马约特岛东部地区。SHOM在火山区域进行的测深调查也为Mayobs项目提供了贡献。IFREMER在MD220-Mayobs巡航期间进行了水柱地球化学测量。在本数据库中，于2019年5月15日至17日对5个站点进行了研究，使用CTD-罗斯特装置中的原位测量。每个站点的样品（每个站点最多16瓶）根据参数在船上和岸上进行分析。质量控制及处理数据包括：原位：盐度（电导率）、温度、深度、溶解氧、浑浊度；船上：pH值、碱度、溶解无机碳；岸上：溶解CO2、CH4、H2、硅酸盐。